[citation needed] The seeds for the construction of the class were laid in by the then WAGR Chief Mechanical Engineer, Tom Marsland, with a proposal for the acquisition of 87 diesel locomotives, including 3 small jetty shunters, 18 diesel shunters and 66 mainline locomotives, later reduced to 48 when railcars were selected for suburban service.

Their light axle load of less than 10 tons meant they could travel on all lines, and the dual cab arrangement eliminated the need for turning.

Although considered as good runners, the eight driving wheels being attached to the rigid main frame caused these locomotives to ride roughly.

At the time of construction, the HST-V8 was an untested concept, though the engine itself was an evolution of a design used successfully in patrol boats during World War Two.

The engines burnt and leaked oil, had underfed bearings, vibrated and popped heads and pistons, and suffered from ring scuffing for most of their lives.

It was only the engineering excellence, and perseverance of Midland Railway Workshops staff that kept the locomotives operating, and performance improving.

[1] It has been noted that the Irish Railways (CIÉ), through the respected Engineer Oliver Bulleid, had "heard" through the British Admiralty that the "Crossley unit gave no trouble".

[5] The Smith Royal Commission into the class identified blind faith in the British manufacturers, and chided the WAGR for ignoring the advice of supervising engineers in the UK who reported problems with the diesel motor during testing.

[11] The last to operate on the public network was XA1401, under the stewardship of Hotham Valley Railway, working a consist of sleeping cars back from Dowerin on 27 August 2004.